This invention relates to a releasable "push in" tube fitting, for use primarily with plastic tubing. The invention permits the conversion of an existing installed prior art tube fitting into a time and cost saving "push in" type fitting for the plumbing of plastic tubing.
At the present time, "push in" fittings are available only as complete units. If it is desired to convert an existing tubing system from conventional compression type fittings to push in type fittings, the existing compression fittings are of no value to the conversion, and must be entirely removed. By means of the present invention, an existing in-place compression fitting body (the part which is threaded into some body of hardware) can be kept in place as part of a conversion to a push in fitting.
Typical tubing lines for the transmission of fluids may include various sizes and shapes of pieces, generally identified as "fittings", to make connections between successive portions of tubing, or between tubing and other hardware. Such fittings include male connectors, male elbows, male branch tees, male run tees, and others. The size range is quite extensive, as it relates both to outside diameters of mating tubing and to thread sizes.
A conventional compression fitting includes a body, a nut, and a sleeve. The body usually has male or female pipe threads at one end, and straight male threads at the other end. The nut is threaded onto the straight male threads. The sleeve fits between the nut and the body. An end of tubing is inserted through the nut and sleeve. Sleeve and tubing are compressed by the action of the nut and body, as they are threaded together, to form a tight sealed connection of fitting and tubing.